Recent discovery of superconductivity (SC) in infinite-layer Sr-doped NdNiO\(_{2}\)  films [1]} and subsequently in hole doped LaNiO\(_2\)  and PrNiO\(_2\)  films [2]}, [3]}, [4]}, [5]} has stimulated
intensive interest in condensed matter community. Despite of many
theoretical and experimental efforts, there are still debates on its
electronic structures and pairing mechanism [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}. The study of possible Ni-based superconductivity was initially stimulated
by cuprates, whose high \(T_c\)  mechanism remains one of the most challenging
topics in past three decades [14]}, [15]}, [16]}, [17]}. Many
attempts have been devoted to exploring new families of high \(T_c\) 
superconductors. Nickelate superconductors are but one latest example of
these efforts.
